Sprinkler systems for fire suppression are used to protect structures which separate or enclose adjacent regions having large temperature differences from one another. Examples of such structures include freezers, balconies of apartments, and loading docks of warehouses. Each of these structures has one or more walls and/or ceilings, which separate a region wherein the temperature is maintained above the freezing point of water from a region where the temperature is maintained below freezing or can drop below freezing.
It is a challenge to provide fire protection to such structures, especially when water is the preferred fire suppressing liquid because measures must be taken to ensure that the water does not freeze within the piping network or the sprinklers. To meet this challenge it is known to position the piping network in the temperature controlled “warm” environment where water within the pipes will not freeze, and to provide “dry” type sprinkler assemblies which extend from the piping network through openings in the ceiling or walls of the structure and into the “cold” or uncontrolled environment. An example of such a dry type sprinkler assembly is disclosed in U.S. Pat. No. 5,967,240, hereby incorporated by reference. Such dry sprinkler assemblies have elongated conduits extending between the sprinkler and the piping network with a valve inside to maintain the sprinkler assembly in a “dry” state, i.e., without water, until the sprinkler is activated by the heat from a fire. A heat sensitive trigger, for example a liquid filled frangible bulb, which breaks when subjected to heat from a fire, opens the sprinkler to permit discharge of the water and also acts to open the valve and allow water to flow from the piping network through the conduit and out through the sprinkler.
In prior art sprinkler systems the dry sprinkler assemblies are rigidly connected to the piping network and therefore do not require supplemental support when they extend through the wall or ceiling of the structure into the cold or uncontrolled environment. However, this rigid design is unforgiving with respect to the relative positioning of the openings and the dry sprinkler assemblies, requiring precise alignment between assembly and opening during construction and installation. It would be advantageous to permit flexibility between the dry sprinkler assembly and the piping network so that a greater variation between opening and sprinkler assembly position could be tolerated, thereby simplifying the design and construction of such systems.